A recording-medium management system comprising: a reproduction part; a
recording part; and a control part. The control part performs a first
through fourth control. The first control is to obtain a first data line
from an authentication region of a recording medium by making the
reproduction part read the authentication region, the authentication
region including a first data pattern of a RAM bit and a ROM bit, the
first data line being corresponding to the first data pattern, the RAM
bit being over-writable of data at least once by a first writing
condition, and the ROM bit being not over-writable of data by the first
writing condition. The second control is to make the recording part
overwrite predetermined data to the RAM bit. The third control is to
obtain a second data line from the recording-medium, the second data line
being corresponding to a second data pattern of the over-written RAM bit
and the ROM bit. The fourth control is to perform an authentication with
regard to the recording medium in reference to the first and second data
lines.